You don’t know with absolute certainty that hell exists, either. So why jump ahead to Siddharta Gautama? First admit what you already don’t know. Keep admitting (as an attitude with life) what you don’t know until only absolute certainty remains. I feel this is also the essence of the teaching of Siddharta Gautama. So, maybe we will find him thusly. Do not worry, this is not different from the teaching of Jesus, either. He was teaching of surrender. I think they expressed the same thing. Just different words. We surrender what we think reality is, to see what reality actually is. Otherwise, isn’t it gambling? You hear one thought from a person, and try to stick to it for the rest of your life, wishing it so much that it is true, not actually knowing whether it is true or not. On what grounds? On the other hand, if you just looked within, you would actually see the knowledge that Jesus told of, that the kingdom of God is within us. But why look within? First admit that you don’t know what you don’t know so that you are free to look. Look at the world if you must, you will find objects, emotions and thoughts. Look at them well, do they truly satisfy you? Are they the truth you seek? Look with sincerity, and admit what they actually are to you. Then your surrender will begin to deepen. The teaching of sincerity of Siddharta Gautama and the teaching of surrender of Jesus, are they different really? Is there a person more accepting of Jesus Christ than Gautama Buddha, who in all evidence, is a master of acceptance himself? I am not a scholar extensively studying Gautama Buddha or Jesus Christ. This answer is based on my impression of these two persons and my own understanding.
If ever there was a hellish dimension, and Gautama Buddha was there, or Jesus Christ was there, they would be unfazed. They would be there to help whomever got stuck there and forgot how to get out. Being aware of their Buddha nature, or their oneness with God, hell wouldn’t faze them. The best thing is not to earn going to heaven. It is to be able to go to hell and not be fazed even by it.